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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * linux/drivers/mmc/core/sdio_irq.c
4 *
5 * Author: Nicolas Pitre
6 * Created: June 18, 2007
7 * Copyright: MontaVista Software Inc.
8 *
9 * Copyright 2008 Pierre Ossman
10 */
11
12#include <linux/kernel.h>
13#include <linux/sched.h>
14#include <uapi/linux/sched/types.h>
15#include <linux/kthread.h>
16#include <linux/export.h>
17#include <linux/wait.h>
18#include <linux/delay.h>
19
20#include <linux/mmc/core.h>
21#include <linux/mmc/host.h>
22#include <linux/mmc/card.h>
23#include <linux/mmc/sdio.h>
24#include <linux/mmc/sdio_func.h>
25
26#include "sdio_ops.h"
27#include "core.h"
28#include "card.h"
29
30static int sdio_get_pending_irqs(struct mmc_host *host, u8 *pending)
31{
32 struct mmc_card *card = host->card;
33 int ret;
34
35 WARN_ON(!host->claimed);
36
37 ret = mmc_io_rw_direct(card, 0, 0, SDIO_CCCR_INTx, 0, pending);
38 if (ret) {
39 pr_debug("%s: error %d reading SDIO_CCCR_INTx\n",
40 mmc_card_id(card), ret);
41 return ret;
42 }
43
44 if (*pending && mmc_card_broken_irq_polling(card) &&
45 !(host->caps & MMC_CAP_SDIO_IRQ)) {
46 unsigned char dummy;
47
48 /* A fake interrupt could be created when we poll SDIO_CCCR_INTx
49 * register with a Marvell SD8797 card. A dummy CMD52 read to
50 * function 0 register 0xff can avoid this.
51 */
52 mmc_io_rw_direct(card, 0, 0, 0xff, 0, &dummy);
53 }
54
55 return 0;
56}
57
58static int process_sdio_pending_irqs(struct mmc_host *host)
59{
60 struct mmc_card *card = host->card;
61 int i, ret, count;
62 bool sdio_irq_pending = host->sdio_irq_pending;
63 unsigned char pending;
64 struct sdio_func *func;
65
66 /* Don't process SDIO IRQs if the card is suspended. */
67 if (mmc_card_suspended(card))
68 return 0;
69
70 /* Clear the flag to indicate that we have processed the IRQ. */
71 host->sdio_irq_pending = false;
72
73 /*
74 * Optimization, if there is only 1 function interrupt registered
75 * and we know an IRQ was signaled then call irq handler directly.
76 * Otherwise do the full probe.
77 */
78 func = card->sdio_single_irq;
79 if (func && sdio_irq_pending) {
80 func->irq_handler(func);
81 return 1;
82 }
83
84 ret = sdio_get_pending_irqs(host, &pending);
85 if (ret)
86 return ret;
87
88 count = 0;
89 for (i = 1; i <= 7; i++) {
90 if (pending & (1 << i)) {
91 func = card->sdio_func[i - 1];
92 if (!func) {
93 pr_warn("%s: pending IRQ for non-existent function\n",
94 mmc_card_id(card));
95 ret = -EINVAL;
96 } else if (func->irq_handler) {
97 func->irq_handler(func);
98 count++;
99 } else {
100 pr_warn("%s: pending IRQ with no handler\n",
101 sdio_func_id(func));
102 ret = -EINVAL;
103 }
104 }
105 }
106
107 if (count)
108 return count;
109
110 return ret;
111}
112
113static void sdio_run_irqs(struct mmc_host *host)
114{
115 mmc_claim_host(host);
116 if (host->sdio_irqs) {
117 process_sdio_pending_irqs(host);
118 if (!host->sdio_irq_pending)
119 host->ops->ack_sdio_irq(host);
120 }
121 mmc_release_host(host);
122}
123
124void sdio_irq_work(struct work_struct *work)
125{
126 struct mmc_host *host =
127 container_of(work, struct mmc_host, sdio_irq_work);
128
129 sdio_run_irqs(host);
130}
131
132void sdio_signal_irq(struct mmc_host *host)
133{
134 host->sdio_irq_pending = true;
135 schedule_work(&host->sdio_irq_work);
136}
137EXPORT_SYMBOL_GPL(sdio_signal_irq);
138
139static int sdio_irq_thread(void *_host)
140{
141 struct mmc_host *host = _host;
142 unsigned long period, idle_period;
143 int ret;
144
145 sched_set_fifo_low(current);
146
147 /*
148 * We want to allow for SDIO cards to work even on non SDIO
149 * aware hosts. One thing that non SDIO host cannot do is
150 * asynchronous notification of pending SDIO card interrupts
151 * hence we poll for them in that case.
152 */
153 idle_period = msecs_to_jiffies(10);
154 period = (host->caps & MMC_CAP_SDIO_IRQ) ?
155 MAX_SCHEDULE_TIMEOUT : idle_period;
156
157 pr_debug("%s: IRQ thread started (poll period = %lu jiffies)\n",
158 mmc_hostname(host), period);
159
160 do {
161 /*
162 * We claim the host here on drivers behalf for a couple
163 * reasons:
164 *
165 * 1) it is already needed to retrieve the CCCR_INTx;
166 * 2) we want the driver(s) to clear the IRQ condition ASAP;
167 * 3) we need to control the abort condition locally.
168 *
169 * Just like traditional hard IRQ handlers, we expect SDIO
170 * IRQ handlers to be quick and to the point, so that the
171 * holding of the host lock does not cover too much work
172 * that doesn't require that lock to be held.
173 */
174 ret = __mmc_claim_host(host, NULL,
175 &host->sdio_irq_thread_abort);
176 if (ret)
177 break;
178 ret = process_sdio_pending_irqs(host);
179 mmc_release_host(host);
180
181 /*
182 * Give other threads a chance to run in the presence of
183 * errors.
184 */
185 if (ret < 0) {
186 set_current_state(TASK_INTERRUPTIBLE);
187 if (!kthread_should_stop())
188 schedule_timeout(HZ);
189 set_current_state(TASK_RUNNING);
190 }
191
192 /*
193 * Adaptive polling frequency based on the assumption
194 * that an interrupt will be closely followed by more.
195 * This has a substantial benefit for network devices.
196 */
197 if (!(host->caps & MMC_CAP_SDIO_IRQ)) {
198 if (ret > 0)
199 period /= 2;
200 else {
201 period++;
202 if (period > idle_period)
203 period = idle_period;
204 }
205 }
206
207 set_current_state(TASK_INTERRUPTIBLE);
208 if (host->caps & MMC_CAP_SDIO_IRQ)
209 host->ops->enable_sdio_irq(host, 1);
210 if (!kthread_should_stop())
211 schedule_timeout(period);
212 set_current_state(TASK_RUNNING);
213 } while (!kthread_should_stop());
214
215 if (host->caps & MMC_CAP_SDIO_IRQ)
216 host->ops->enable_sdio_irq(host, 0);
217
218 pr_debug("%s: IRQ thread exiting with code %d\n",
219 mmc_hostname(host), ret);
220
221 return ret;
222}
223
224static int sdio_card_irq_get(struct mmc_card *card)
225{
226 struct mmc_host *host = card->host;
227
228 WARN_ON(!host->claimed);
229
230 if (!host->sdio_irqs++) {
231 if (!(host->caps2 & MMC_CAP2_SDIO_IRQ_NOTHREAD)) {
232 atomic_set(&host->sdio_irq_thread_abort, 0);
233 host->sdio_irq_thread =
234 kthread_run(sdio_irq_thread, host,
235 "ksdioirqd/%s", mmc_hostname(host));
236 if (IS_ERR(host->sdio_irq_thread)) {
237 int err = PTR_ERR(host->sdio_irq_thread);
238 host->sdio_irqs--;
239 return err;
240 }
241 } else if (host->caps & MMC_CAP_SDIO_IRQ) {
242 host->ops->enable_sdio_irq(host, 1);
243 }
244 }
245
246 return 0;
247}
248
249static int sdio_card_irq_put(struct mmc_card *card)
250{
251 struct mmc_host *host = card->host;
252
253 WARN_ON(!host->claimed);
254
255 if (host->sdio_irqs < 1)
256 return -EINVAL;
257
258 if (!--host->sdio_irqs) {
259 if (!(host->caps2 & MMC_CAP2_SDIO_IRQ_NOTHREAD)) {
260 atomic_set(&host->sdio_irq_thread_abort, 1);
261 kthread_stop(host->sdio_irq_thread);
262 } else if (host->caps & MMC_CAP_SDIO_IRQ) {
263 host->ops->enable_sdio_irq(host, 0);
264 }
265 }
266
267 return 0;
268}
269
270/* If there is only 1 function registered set sdio_single_irq */
271static void sdio_single_irq_set(struct mmc_card *card)
272{
273 struct sdio_func *func;
274 int i;
275
276 card->sdio_single_irq = NULL;
277 if ((card->host->caps & MMC_CAP_SDIO_IRQ) &&
278 card->host->sdio_irqs == 1) {
279 for (i = 0; i < card->sdio_funcs; i++) {
280 func = card->sdio_func[i];
281 if (func && func->irq_handler) {
282 card->sdio_single_irq = func;
283 break;
284 }
285 }
286 }
287}
288
289/**
290 * sdio_claim_irq - claim the IRQ for a SDIO function
291 * @func: SDIO function
292 * @handler: IRQ handler callback
293 *
294 * Claim and activate the IRQ for the given SDIO function. The provided
295 * handler will be called when that IRQ is asserted. The host is always
296 * claimed already when the handler is called so the handler should not
297 * call sdio_claim_host() or sdio_release_host().
298 */
299int sdio_claim_irq(struct sdio_func *func, sdio_irq_handler_t *handler)
300{
301 int ret;
302 unsigned char reg;
303
304 if (!func)
305 return -EINVAL;
306
307 pr_debug("SDIO: Enabling IRQ for %s...\n", sdio_func_id(func));
308
309 if (func->irq_handler) {
310 pr_debug("SDIO: IRQ for %s already in use.\n", sdio_func_id(func));
311 return -EBUSY;
312 }
313
314 ret = mmc_io_rw_direct(func->card, 0, 0, SDIO_CCCR_IENx, 0, ®);
315 if (ret)
316 return ret;
317
318 reg |= 1 << func->num;
319
320 reg |= 1; /* Master interrupt enable */
321
322 ret = mmc_io_rw_direct(func->card, 1, 0, SDIO_CCCR_IENx, reg, NULL);
323 if (ret)
324 return ret;
325
326 func->irq_handler = handler;
327 ret = sdio_card_irq_get(func->card);
328 if (ret)
329 func->irq_handler = NULL;
330 sdio_single_irq_set(func->card);
331
332 return ret;
333}
334EXPORT_SYMBOL_GPL(sdio_claim_irq);
335
336/**
337 * sdio_release_irq - release the IRQ for a SDIO function
338 * @func: SDIO function
339 *
340 * Disable and release the IRQ for the given SDIO function.
341 */
342int sdio_release_irq(struct sdio_func *func)
343{
344 int ret;
345 unsigned char reg;
346
347 if (!func)
348 return -EINVAL;
349
350 pr_debug("SDIO: Disabling IRQ for %s...\n", sdio_func_id(func));
351
352 if (func->irq_handler) {
353 func->irq_handler = NULL;
354 sdio_card_irq_put(func->card);
355 sdio_single_irq_set(func->card);
356 }
357
358 ret = mmc_io_rw_direct(func->card, 0, 0, SDIO_CCCR_IENx, 0, ®);
359 if (ret)
360 return ret;
361
362 reg &= ~(1 << func->num);
363
364 /* Disable master interrupt with the last function interrupt */
365 if (!(reg & 0xFE))
366 reg = 0;
367
368 ret = mmc_io_rw_direct(func->card, 1, 0, SDIO_CCCR_IENx, reg, NULL);
369 if (ret)
370 return ret;
371
372 return 0;
373}
374EXPORT_SYMBOL_GPL(sdio_release_irq);
375
1/*
2 * linux/drivers/mmc/core/sdio_irq.c
3 *
4 * Author: Nicolas Pitre
5 * Created: June 18, 2007
6 * Copyright: MontaVista Software Inc.
7 *
8 * Copyright 2008 Pierre Ossman
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; either version 2 of the License, or (at
13 * your option) any later version.
14 */
15
16#include <linux/kernel.h>
17#include <linux/sched.h>
18#include <linux/kthread.h>
19#include <linux/export.h>
20#include <linux/wait.h>
21#include <linux/delay.h>
22
23#include <linux/mmc/core.h>
24#include <linux/mmc/host.h>
25#include <linux/mmc/card.h>
26#include <linux/mmc/sdio.h>
27#include <linux/mmc/sdio_func.h>
28
29#include "sdio_ops.h"
30
31static int process_sdio_pending_irqs(struct mmc_host *host)
32{
33 struct mmc_card *card = host->card;
34 int i, ret, count;
35 unsigned char pending;
36 struct sdio_func *func;
37
38 /*
39 * Optimization, if there is only 1 function interrupt registered
40 * and we know an IRQ was signaled then call irq handler directly.
41 * Otherwise do the full probe.
42 */
43 func = card->sdio_single_irq;
44 if (func && host->sdio_irq_pending) {
45 func->irq_handler(func);
46 return 1;
47 }
48
49 ret = mmc_io_rw_direct(card, 0, 0, SDIO_CCCR_INTx, 0, &pending);
50 if (ret) {
51 pr_debug("%s: error %d reading SDIO_CCCR_INTx\n",
52 mmc_card_id(card), ret);
53 return ret;
54 }
55
56 if (pending && mmc_card_broken_irq_polling(card) &&
57 !(host->caps & MMC_CAP_SDIO_IRQ)) {
58 unsigned char dummy;
59
60 /* A fake interrupt could be created when we poll SDIO_CCCR_INTx
61 * register with a Marvell SD8797 card. A dummy CMD52 read to
62 * function 0 register 0xff can avoid this.
63 */
64 mmc_io_rw_direct(card, 0, 0, 0xff, 0, &dummy);
65 }
66
67 count = 0;
68 for (i = 1; i <= 7; i++) {
69 if (pending & (1 << i)) {
70 func = card->sdio_func[i - 1];
71 if (!func) {
72 pr_warning("%s: pending IRQ for "
73 "non-existent function\n",
74 mmc_card_id(card));
75 ret = -EINVAL;
76 } else if (func->irq_handler) {
77 func->irq_handler(func);
78 count++;
79 } else {
80 pr_warning("%s: pending IRQ with no handler\n",
81 sdio_func_id(func));
82 ret = -EINVAL;
83 }
84 }
85 }
86
87 if (count)
88 return count;
89
90 return ret;
91}
92
93static int sdio_irq_thread(void *_host)
94{
95 struct mmc_host *host = _host;
96 struct sched_param param = { .sched_priority = 1 };
97 unsigned long period, idle_period;
98 int ret;
99
100 sched_setscheduler(current, SCHED_FIFO, ¶m);
101
102 /*
103 * We want to allow for SDIO cards to work even on non SDIO
104 * aware hosts. One thing that non SDIO host cannot do is
105 * asynchronous notification of pending SDIO card interrupts
106 * hence we poll for them in that case.
107 */
108 idle_period = msecs_to_jiffies(10);
109 period = (host->caps & MMC_CAP_SDIO_IRQ) ?
110 MAX_SCHEDULE_TIMEOUT : idle_period;
111
112 pr_debug("%s: IRQ thread started (poll period = %lu jiffies)\n",
113 mmc_hostname(host), period);
114
115 do {
116 /*
117 * We claim the host here on drivers behalf for a couple
118 * reasons:
119 *
120 * 1) it is already needed to retrieve the CCCR_INTx;
121 * 2) we want the driver(s) to clear the IRQ condition ASAP;
122 * 3) we need to control the abort condition locally.
123 *
124 * Just like traditional hard IRQ handlers, we expect SDIO
125 * IRQ handlers to be quick and to the point, so that the
126 * holding of the host lock does not cover too much work
127 * that doesn't require that lock to be held.
128 */
129 ret = __mmc_claim_host(host, &host->sdio_irq_thread_abort);
130 if (ret)
131 break;
132 ret = process_sdio_pending_irqs(host);
133 host->sdio_irq_pending = false;
134 mmc_release_host(host);
135
136 /*
137 * Give other threads a chance to run in the presence of
138 * errors.
139 */
140 if (ret < 0) {
141 set_current_state(TASK_INTERRUPTIBLE);
142 if (!kthread_should_stop())
143 schedule_timeout(HZ);
144 set_current_state(TASK_RUNNING);
145 }
146
147 /*
148 * Adaptive polling frequency based on the assumption
149 * that an interrupt will be closely followed by more.
150 * This has a substantial benefit for network devices.
151 */
152 if (!(host->caps & MMC_CAP_SDIO_IRQ)) {
153 if (ret > 0)
154 period /= 2;
155 else {
156 period++;
157 if (period > idle_period)
158 period = idle_period;
159 }
160 }
161
162 set_current_state(TASK_INTERRUPTIBLE);
163 if (host->caps & MMC_CAP_SDIO_IRQ) {
164 mmc_host_clk_hold(host);
165 host->ops->enable_sdio_irq(host, 1);
166 mmc_host_clk_release(host);
167 }
168 if (!kthread_should_stop())
169 schedule_timeout(period);
170 set_current_state(TASK_RUNNING);
171 } while (!kthread_should_stop());
172
173 if (host->caps & MMC_CAP_SDIO_IRQ) {
174 mmc_host_clk_hold(host);
175 host->ops->enable_sdio_irq(host, 0);
176 mmc_host_clk_release(host);
177 }
178
179 pr_debug("%s: IRQ thread exiting with code %d\n",
180 mmc_hostname(host), ret);
181
182 return ret;
183}
184
185static int sdio_card_irq_get(struct mmc_card *card)
186{
187 struct mmc_host *host = card->host;
188
189 WARN_ON(!host->claimed);
190
191 if (!host->sdio_irqs++) {
192 atomic_set(&host->sdio_irq_thread_abort, 0);
193 host->sdio_irq_thread =
194 kthread_run(sdio_irq_thread, host, "ksdioirqd/%s",
195 mmc_hostname(host));
196 if (IS_ERR(host->sdio_irq_thread)) {
197 int err = PTR_ERR(host->sdio_irq_thread);
198 host->sdio_irqs--;
199 return err;
200 }
201 }
202
203 return 0;
204}
205
206static int sdio_card_irq_put(struct mmc_card *card)
207{
208 struct mmc_host *host = card->host;
209
210 WARN_ON(!host->claimed);
211 BUG_ON(host->sdio_irqs < 1);
212
213 if (!--host->sdio_irqs) {
214 atomic_set(&host->sdio_irq_thread_abort, 1);
215 kthread_stop(host->sdio_irq_thread);
216 }
217
218 return 0;
219}
220
221/* If there is only 1 function registered set sdio_single_irq */
222static void sdio_single_irq_set(struct mmc_card *card)
223{
224 struct sdio_func *func;
225 int i;
226
227 card->sdio_single_irq = NULL;
228 if ((card->host->caps & MMC_CAP_SDIO_IRQ) &&
229 card->host->sdio_irqs == 1)
230 for (i = 0; i < card->sdio_funcs; i++) {
231 func = card->sdio_func[i];
232 if (func && func->irq_handler) {
233 card->sdio_single_irq = func;
234 break;
235 }
236 }
237}
238
239/**
240 * sdio_claim_irq - claim the IRQ for a SDIO function
241 * @func: SDIO function
242 * @handler: IRQ handler callback
243 *
244 * Claim and activate the IRQ for the given SDIO function. The provided
245 * handler will be called when that IRQ is asserted. The host is always
246 * claimed already when the handler is called so the handler must not
247 * call sdio_claim_host() nor sdio_release_host().
248 */
249int sdio_claim_irq(struct sdio_func *func, sdio_irq_handler_t *handler)
250{
251 int ret;
252 unsigned char reg;
253
254 BUG_ON(!func);
255 BUG_ON(!func->card);
256
257 pr_debug("SDIO: Enabling IRQ for %s...\n", sdio_func_id(func));
258
259 if (func->irq_handler) {
260 pr_debug("SDIO: IRQ for %s already in use.\n", sdio_func_id(func));
261 return -EBUSY;
262 }
263
264 ret = mmc_io_rw_direct(func->card, 0, 0, SDIO_CCCR_IENx, 0, ®);
265 if (ret)
266 return ret;
267
268 reg |= 1 << func->num;
269
270 reg |= 1; /* Master interrupt enable */
271
272 ret = mmc_io_rw_direct(func->card, 1, 0, SDIO_CCCR_IENx, reg, NULL);
273 if (ret)
274 return ret;
275
276 func->irq_handler = handler;
277 ret = sdio_card_irq_get(func->card);
278 if (ret)
279 func->irq_handler = NULL;
280 sdio_single_irq_set(func->card);
281
282 return ret;
283}
284EXPORT_SYMBOL_GPL(sdio_claim_irq);
285
286/**
287 * sdio_release_irq - release the IRQ for a SDIO function
288 * @func: SDIO function
289 *
290 * Disable and release the IRQ for the given SDIO function.
291 */
292int sdio_release_irq(struct sdio_func *func)
293{
294 int ret;
295 unsigned char reg;
296
297 BUG_ON(!func);
298 BUG_ON(!func->card);
299
300 pr_debug("SDIO: Disabling IRQ for %s...\n", sdio_func_id(func));
301
302 if (func->irq_handler) {
303 func->irq_handler = NULL;
304 sdio_card_irq_put(func->card);
305 sdio_single_irq_set(func->card);
306 }
307
308 ret = mmc_io_rw_direct(func->card, 0, 0, SDIO_CCCR_IENx, 0, ®);
309 if (ret)
310 return ret;
311
312 reg &= ~(1 << func->num);
313
314 /* Disable master interrupt with the last function interrupt */
315 if (!(reg & 0xFE))
316 reg = 0;
317
318 ret = mmc_io_rw_direct(func->card, 1, 0, SDIO_CCCR_IENx, reg, NULL);
319 if (ret)
320 return ret;
321
322 return 0;
323}
324EXPORT_SYMBOL_GPL(sdio_release_irq);
325